indow.onload = function() {
	var wrap = document.getElementById('banner_pc')
	var pic = document.getElementById('pic').getElementsByTagName("li")
	var list = document.getElementById('list').getElementsByTagName('li')
	var index = 0
	var timer = null;

	// 定义并调用自动播放函数
	timer = setInterval(autoPlay, 1000);

	// 鼠标划过整个容器时停止自动播放
	wrap.onmouseover = function() {
		clearInterval(timer);
	}

	// 鼠标离开整个容器时继续播放至下一张
	wrap.onmouseout = function() {
		timer = setInterval(autoPlay, 2000);
	}
	// 遍历所有数字导航实现划过切换至对应的图片
	for (var i = 0; i < list.length; i++) {
		list[i].onmouseover = function() {
			clearInterval(timer);
			index = this.innerText - 1;
			changePic(index);
		};
	}
	;

	function autoPlay() {
		if (++index >= pic.length)
			index = 0;
		changePic(index);
	}

	// 定义图片切换函数
	function changePic(curIndex) {
		for (var i = 0; i < pic.length; ++i) {
			pic[i].style.display = "none";
			list[i].className = "";
		}
		pic[curIndex].style.display = "block";
		list[curIndex].className = "on";
	}

};